Editor’s Note: This Article of the Month is based on Al-Khatib SM, Hellkamp AS, Hernandez AF et al. Trends in Use of Implantable Cardioverter-Defibrillator Therapy Among Patients Hospitalized for Heart Failure. Circulation 2012; 125:1094-1101.

Summary

Despite clinical trial evidence^1-4 and guidelines recommendations,⁵ many potentially eligible patients are not provided ICD therapy.^6-9 Previous analyses of ICD utilization from data sets spanning 1999-2005⁶ and 2005-2007⁷ showed significant disparity across sex and racial lines. The reasons for this disparity and for overall ICD underutilization are not well understood but are likely multifactorial. This study examines ICD utilization from 2005-2009 to determine whether there has been any change following efforts to increase awareness of these issues.

Methods

The Get With the Guidelines-Heart Failure (GWTG-HF) database from 2005-2009 was queried for Medicare patients hospitalized for HF and discharged to home. Patients were excluded for LVEF> 35% (or lack of a documented LVEF), newly diagnosed HF, MI within 40 days, recent coronary revascularization, or a documented life expectancy of less than one year. For patients with multiple HF hospitalizations, only the first hospitalization was included in the analysis. The remaining 11,880 unique patients were examined for the absence or presence of an ICD (including CRT-D) or a prescription for outpatient ICD/CRT-D implantation.

Results

Overall ICD use increased from 30.2% in 2005 to 42.4% in 2007, but it was unchanged in 2008 and 2009. Compared to patients who received or were prescribed an ICD, untreated patients were older (79 vs. 75 years, p<0.0001), female (42.4% vs. 26.5%, p<0.0001) or non-white (24.0% vs. 20.5%, p<0.0001). Untreated patients were more likely to have anemia (15.0% vs. 12.3%, p<0.0001), cerebrovascular disease (13.9% vs. 12.9%, p≤0.005) or hypertension (71.5% vs. 68.4%, p<0.0001). Implanted or prescribed patients had a higher proportion of concomitant cardiovascular diseases, including AF (36.5% vs. 31.9%, p<0.0001), ischemic heart disease (75.5% vs. 65.5%, p<0.0001) and hyperlipidemia (53.4% vs. 42.1%, p<0.0001).

All four demographic groups (white men, white women, black men and black women) showed an increase in ICD utilization from 2005 to 2009, but the degree of these increases varied by race and sex. ICD utilization rates for these groups were adjusted for patient and hospital factors, then divided into time frames labeled “past” (January 2005 to December 2007) and “present” (January to December 2009). When compared to prior rates of ICD utilization in white men, improvements were seen in black women (present odds ratio 0.60 [CI 0.42-0.85], past 0.48 [0.33-0.71]), white women (present 0.61 [0.50-0.74], past 0.57 [0.50-0.65]) and black men (present 0.91 [0.67-1.25], past 0.73 [0.53-1.02]). Compared to whites, present ICD utilization for blacks was not significantly different (0.95 [0.73-1.25]) despite a broader disparity in the past (0.79 [0.60-1.03]). However, the disparity in ICD utilization for women versus men did not improve compared to previous rates (0.63 [0.50-0.78] vs. 0.65 [0.52-0.81]).

Conclusion

Institutions participating in the GWTG-HF quality improvement program demonstrated a significant increase in ICD utilization from 2005 to 2007. By 2009, the previously described racial disparities in ICD use were no longer present; however, women were still significantly less likely to receive indicated ICD therapy than men.

Perspective

Sudden cardiac arrest continues to be a leading cause of cardiovascular mortality. Despite randomized clinical trial evidence and guidelines recommendations, ICD utilization remains limited. However, ICD use in the GWTG-HF quality improvement program significantly increased overall across all demographic groups from 2005 to 2007, but it was merely stable in 2008 and 2009. Importantly, blacks now appear to have similar access to ICD therapy when compared to same-sex whites. Unfortunately, women remain significantly less likely than men to receive ICD therapy. Overall, this study’s findings are encouraging, as it suggests that participation in a systematic program to encourage guidelines conformation can partially overcome the poorly understood but well-documented lack of appropriate ICD utilization.This is consistent with previous studies that have shown that guidelines-recommended HF therapies tracked as third party performance measures had higher utilization than untracked therapies.^8,9 As we move closer to mandatory “pay for performance” and public reporting of patient outcomes, ensuring consistent, equitable delivery of proven, guidelines-indicated therapies will be increasingly important.Given the plateau of ICD utilization seen in 2008 and 2009, as well as the ongoing disparity for ICD use in women, it is uncertain if therapy awareness efforts and voluntary quality improvement programs can adequately address ICD underutilization and disparate utilization.

In July 2010, the Joint Commission began development of a new set of proposed performance measures for Advanced Certification in Heart Failure. “ICD counseling for LVSD” and “Cardiac Resynchronization Therapy” were incorporated into a set of 13 HF performance measures which underwent pilot testing from November 2011 through April 2012.¹⁰ The results of this pilot have not been disclosed publicly. If these proposed measures are ultimately incorporated into hospital-based, national performance measures, then higher rates of utilization might be achieved for ICDs. It is unclear, however, if this would eliminate sex-based disparities.

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References

1. Moss AJ, Hall WJ, Cannom DS, et al. Improved survival with an implanted defibrillator in patients with coronary disease at high risk for ventricular arrhythmia. Multicenter Automatic Defibrillator Implantation Trial Investigators. N Engl J Med 1996; 335:1933-40.
2. Buxton AE, Lee KL, Fisher JD, et al. A randomized study of the prevention of sudden death in patients with coronary artery disease. Multicenter Unsustained Tachycardia Trial Investigators. N Engl J Med 1999; 341:1882-90.
3. Moss AJ, Zareba W, Hall WJ, et al.; Multicenter Automatic Defibrillator Implantation Trial II Investigators. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. N Engl J Med 2002; 346:877-83.
4. Bardy GH, Lee KL, Mark DB, et al.; Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) Investigators. Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. N Engl J Med 2005; 352:225-37.
5. Epstein AE, DiMarco JP, Ellenbogen KA, et al; ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities. Circulation 117:e350-408
6. Curtis LH, Al-Khatib SM, Shea AM, Hammill BG, Hernandez AF, Schulman KA. Sex differences in the use of implantable cardioverter-defibrillators for primary and secondary prevention of sudden cardiac death. JAMA 2007; 298:1517-24.
7. Hernandez AF, Fonarow GC, Liang L, et al. Sex and racial differences in the use of implantable cardioverter-defibrillators among patients hospitalized with heart failure. JAMA 2007; 298:1525-32.
8. Yancy CW, Fonarow GC, Albert NM, et al. Influence of patient age and sex on delivery of guideline-recommended heart failure care in the outpatient cardiology practice setting: findings from IMPROVE HF. Am Heart J 2009; 157:754-62.e2.
9. Shah B, Hernandez AF, Liang L, et al.; Get With The Guidelines Steering Committee. Hospital variation and characteristics of implantable cardioverter-defibrillator use in patients with heart failure: data from the GWTG-HF (Get With The Guidelines-Heart Failure) registry. J Am Coll Cardiol 2009; 53:416-22.
10. The Joint Commission. Advanced Certification in Heart Failure Measures. August 8, 2012. http://www.jointcommission.org/advanced_certification_in_heart_failure_measures/ [Last accessed August, 29, 2012].

Keywords: Defibrillators, Implantable

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